The invention relates to a method of constructing an assembly of at least two metal parts such as a rolling bearing with a housing or shaft in mating or fitting contact with each other and with minimal movement relative to each other under an alternating load, in such manner to avoid fretting corrosion at the surfaces in contact.
Fretting corrosion is defined as a phenomenon of wear that occurs between two surfaces subjected to a relative vibratory motion of comparatively small amplitude. In a rolling bearing assembly such motions occur between the inner ring and the shaft and between the outer ring and the housing because of the alternating stresses in the faces as the rolling elements pass along them with resulting elastic deformations in the rings.
Heretofore, to avoid fretting corrosion close press fits have been employed in order to reduce elastic deformations. In the first place, this cannot completely prevent the occurrence of fretting corrosion under high dynamic stresses in a rolling bearing assembly, and in the second place a press fit is not always available. When installing a rolling bearing in the axle box or housing of a bearing in railroad rolling stock, for example, or in a doubly supported shaft where one loose bearing is used to compensate play in the shaft, a press fit would present formidable problems.
The object of the invention is to improve known methods of minimizing fretting corrosion in such manner that in the resulting assembly no fretting corrosion will occur even under extremely high dynamic stresses, and no press fit is required.